This invention relates to measurement of temperatures in molten metal baths. More specifically the invention relates to a protective assembly for a support pole system for a temperature measuring thermocouple particularly adapted for use in molten metals.
Thermocouples or similar immersible temperature measuring devices are conventionally immersed in a molten metal bath in a metal processing vessel in order to measure the temperature and to control the process conditions such as the heat being supplied. It is desirable that such immersible thermocouple support poles are protected from excessive heat in order to extend the functional service life of signal carrying wires contained therein. Such molten metal containing vessels are used, for example, in refining of steel, iron, aluminum, copper, brass or bronze. It is also important that the support assemblies be easy to use and economical.
It is conventional to use cardboard tubes attached to the thermocouples to protect a hollow metal pole wherein insulated electrical wires, connected by means of appropriate electrical connectors to the immersible thermocouple, are concealed. Excessive exposure to heat significantly shortens the life of the thermocouple support assemblies. Operating conditions are typically are in the 2600.degree. F. range in a foundry and 3100.degree. F. in a steel shop.
Cardboard protective tubes are expendable but create undesirable air and metal pollution. Over a period of time, such tubes also add an undesirable expense to the metal processing procedure. Thus, a need has existed for improved heat-shielded support systems for both single use and reusable thermocouples.